I do...of sorts. I actually have been working on a pattern for a crystal tassle top mini-class. And decided that a crystal ball would be good to add to the class as well....it makes a super cool closure.
Just work a little perle cotton or crochet thread loop (cast on stitch over 4 threads)...or use a child's hair elastic band...to fit over the ball, which is treated like a button. Now, to just get the charts drawn and the instructions written.